While NWX gets better and better with each new release, there's one bug which isn't fixed yet: When you check the "Allow Hyphenation" option, hyphenation works (more or less) reasonably well during working with an open document but after closing the document hyphenation will be lost upon re-start. Funny thing is: There seems to be kind of a workaround: After re-start you check "Show Invisibles" and hyphenation will appear again.
I wonder if I'm doing something wrong or if that's something wich needs to be tended to...
BTW: A "soft hyphenation" feature in order to insert hyphens manually or to override the suggestions by the program would be fine since sometimes automatic hyphenation tends to produce weird results.